Additive protective effects of sacubitril/valsartan and bosentan on vascular remodelling in experimental pulmonary hypertension

Sacubitril/Valsartan Improves Hemodynamic Parameters of Pulmonary and Systemic Circulation in Patients Awaiting Heart Transplantation

Background/Objectives: Heart transplantation (HTX) is the definitive treatment for advanced heart failure (AdHF). The angiotensin receptor neprilysin inhibitor (ARNI) sacubitril/valsartan (S/V) has been shown to reduce heart failure (HF) hospitalizations and mortality when compared to conventionally administered HF medications (i.e. angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs)). Nevertheless, limited data are available on the hemodynamic (HD) effects of ARNI in patients with AdHF. Therefore, the aim of the present study was to compare echocardiographic, laboratory, and HD parameters relevant to HF before and after switching to ARNI in patients with AdHF awaiting HTX. Methods: A retrospective analysis was conducted utilizing available data on HD parameters, N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, data on kidney function, HF therapy, and comorbidities. The study cohort comprised 13 AdHF patients (3 women, 10 men; mean age 56.4 ± 9 years) of whom 53.8% presented with non-ischemic and 46.2% with ischemic etiology. All patients were awaiting heart transplantation (HTX) and were transitioned to ARNI therapy between 2018 and 2021. Results: After switching to ARNI, we observed significant improvements: in left ventricular ejection fraction (LVEF: 27.27 ± 1.04% vs. 23.65 ± 1.02%, p = 0.03; data are given as mean ± SEM after vs. before ARNI therapy, respectively), cardiac output (CO: 4.90 ± 0.35 L/min vs. 3.83 ± 0.24 L/min, p = 0.013), and stroke volume (SV: 70.9 ± 5.9 mL vs. 55.5 ± 4.12 mL, p = 0.013). Significant reductions in systemic vascular resistance (SVR: 1188 ± 79.8 vs. 1600 ± 100 DS/cm5, p = 0.004) and pulmonary vascular resistance (PVR: 232.5 ± 34.8 vs. 278.9 ± 31.7 DS/cm5, p = 0.04) were also noted. Central venous pressure (CVP), pulmonary arterial systolic and diastolic pressures (PAPs and PAPd), pulmonary capillary wedge pressure (PCWP), and NT-proBNP levels did not exhibit significant changes upon ARNI administration. Conclusions: Early transition to ARNI therapy offers significant benefits for invasively measured hemodynamic parameters in patients with AdHF, potentially aiding in the stabilization and improvement of this vulnerable patient population.

Qianyang Yuyin granules alleviate hypertension-induced vascular remodeling by inhibiting the phenotypic switch of vascular smooth muscle cells

ETHNOPHARMACOLOGICAL RELEVANCE

Qianyang Yuyin granules (QYYY) have been used clinically to treat hypertension for over two decades. Previous clinical trials have shown that QYYY can improve vascular elastic function in hypertensive patients. However, the underlying pharmacological mechanism is unclear.

AIM OF THE STUDY

To elucidate the effects and mechanisms of QYYY on vascular remodeling using a multidisciplinary approach that includes network pharmacology, proteomics, and both in vitro and in vivo experiments.

MATERIALS AND METHODS

The main components of QYYY were identified using ultra-high-performance liquid chromatography and high-resolution mass spectrometry. Network pharmacology and molecular docking were employed to predict QYYY's primary active ingredients, potential therapeutic targets and intervention pathways in hypertensive vascular remodeling. We induced hypertension in male C57BL/6 mice by infusing angiotensin II (Ang II) via osmotic minipumps, and performed pre-treatment with QYYY or Sacubitril/valsartan (Entresto). Blood pressure was monitored in vivo, followed by the extraction of aortas to examine pathological structural changes and alterations in protein expression patterns. The expression and location of proteins involved in the HIF-1α/TWIST1/P-p65 signaling pathway were investigated, as well as markers of vascular smooth muscle cells (VSMCs) phenotypic switch. In vitro, we studied the effects of QYYY water extract on Ang II-stimulated human aortic VSMCs. We investigated whether QYYY could affect the HIF-1α/TWIST1/P-p65 signaling pathway, thereby ameliorating apoptosis, autophagy, and phenotype switch in VSMCs.

RESULTS

We identified 62 main compounds in QYYY, combined with network pharmacology, speculated 827 potentially active substances, and explored 1021 therapeutic targets. The KEGG pathway analysis revealed that the mechanisms of action associated with QYYY therapy potentially encompass various biological processes, including metabolic pathways, TNF signaling pathways, apoptosis, Ras signaling pathways, HIF-1 signaling pathways, autophagy-animal pathways. In hypertensive mice, QYYY restored abnormally elevated blood pressure, vascular remodeling, and inflammation with a dose-response relationship while altering abnormal protein patterns. In vitro, QYYY could inhibit abnormal proliferation, migration, intracellular Ca2+ accumulation and cytoskeletal changes of VSMCs. It improved mitochondrial function, reduced ROS levels, stabilized membrane potential, prevented cell death, and reduced overproduction of TGF-β1, TNF-a, and IL-1β.

CONCLUSION

QYYY may be able to inhibit the overactivation of the HIF-1α/TWIST1/P-p65 signaling pathway, improve the phenotypic switch, and balance apoptosis and autophagy in VSMCs, thereby effectively improving vascular remodeling caused by hypertension.

Impact of sodium-glucose cotransporter-2 inhibitors on pulmonary vascular cell function and arterial remodeling

Sodium-glucose cotransporter-2 (SGLT-2) inhibitors represent a cutting-edge class of oral antidiabetic therapeutics that operate through selective inhibition of glucose reabsorption in proximal renal tubules, consequently augmenting urinary glucose excretion and attenuating blood glucose levels. Extensive clinical investigations have demonstrated their profound cardiovascular efficacy. Parallel basic science research has elucidated the mechanistic pathways through which diverse SGLT-2 inhibitors beneficially modulate pulmonary vascular cells and arterial remodeling. Specifically, these inhibitors exhibit promising potential in enhancing pulmonary vascular endothelial cell function, suppressing pulmonary smooth muscle cell proliferation and migration, reversing pulmonary arterial remodeling, and maintaining hemodynamic equilibrium. This comprehensive review synthesizes current literature to delineate the mechanisms by which SGLT-2 inhibitors enhance pulmonary vascular cell function and reverse pulmonary remodeling, thereby offering novel therapeutic perspectives for pulmonary vascular diseases.

Current Overview of the Biology and Pharmacology in Sugen/Hypoxia-Induced Pulmonary Hypertension in Rats

The Sugen 5416/hypoxia (Su/Hx) rat model of pulmonary arterial hypertension (PAH) demonstrates most of the distinguishing features of PAH in humans, including increased wall thickness and obstruction of the small pulmonary arteries along with plexiform lesion formation. Recently, significant advancement has been made describing the epidemiology, genomics, biochemistry, physiology, and pharmacology in Su/Hx challenge in rats. For example, there are differences in the overall reactivity to Su/Hx challenge in different rat strains and only female rats respond to estrogen treatments. These conditions are also encountered in human subjects with PAH. Also, there is a good translation in both the biochemical and metabolic pathways in the pulmonary vasculature and right heart between Su/Hx rats and humans, particularly during the transition from the adaptive to the nonadaptive phase of right heart failure. Noninvasive techniques such as echocardiography and magnetic resonance imaging have recently been used to evaluate the progression of the pulmonary vascular and cardiac hemodynamics, which are important parameters to monitor the efficacy of drug treatment over time. From a pharmacological perspective, most of the compounds approved clinically for the treatment of PAH are efficacious in Su/Hx rats. Several compounds that show efficacy in Su/Hx rats have advanced into phase II/phase III studies in humans with positive results. Results from these drug trials, if successful, will provide additional treatment options for patients with PAH and will also further validate the excellent translation that currently exists between Su/Hx rats and the human PAH condition.

Unlocking the Potential: Angiotensin Receptor Neprilysin and Sodium Glucose Co-Transporter 2 Inhibitors for Right Ventricle Dysfunction in Heart Failure

This review article examines the mechanism of action of Angiotensin Receptor-Neprilysin Inhibitors (ARNIs) and Sodium-Glucose Co-Transporter 2 Inhibitors (SGLT2is) in managing chronic right ventricular (RV) dysfunction. Despite advancements in heart failure (HF) treatment, RV dysfunction remains a significant contributor to morbidity and mortality. This article explores the The article explores the impact of ARNIs and SGLT2is on RV function based on clinical and preclinical evidence, and the potential benefits of combined therapy. It highlights the need for further research to optimize patient outcomes and suggests that RV function should be considered in future clinical trials as part of risk stratification for HF therapies. This review underscores the importance of the early initiation of ARNIs and SGLT2is as per guideline-directed medical therapy for eligible HFrEF and HFpEF patients to improve co-existing RV dysfunction.

Pulmonary Vascular Responses to Chronic Intermittent Hypoxia in a Guinea Pig Model of Obstructive Sleep Apnea

Experimental evidence suggests that chronic intermittent hypoxia (CIH), a major hallmark of obstructive sleep apnea (OSA), boosts carotid body (CB) responsiveness, thereby causing increased sympathetic activity, arterial and pulmonary hypertension, and cardiovascular disease. An enhanced circulatory chemoreflex, oxidative stress, and NO signaling appear to play important roles in these responses to CIH in rodents. Since the guinea pig has a hypofunctional CB (i.e., it is a natural CB knockout), in this study we used it as a model to investigate the CB dependence of the effects of CIH on pulmonary vascular responses, including those mediated by NO, by comparing them with those previously described in the rat. We have analyzed pulmonary artery pressure (PAP), the hypoxic pulmonary vasoconstriction (HPV) response, endothelial function both in vivo and in vitro, and vascular remodeling (intima-media thickness, collagen fiber content, and vessel lumen area). We demonstrate that 30 days of the exposure of guinea pigs to CIH (FiO2, 5% for 40 s, 30 cycles/h) induces pulmonary artery remodeling but does not alter endothelial function or the contractile response to phenylephrine (PE) in these arteries. In contrast, CIH exposure increased the systemic arterial pressure and enhanced the contractile response to PE while decreasing endothelium-dependent vasorelaxation to carbachol in the aorta without causing its remodeling. We conclude that since all of these effects are independent of CB sensitization, there must be other oxygen sensors, beyond the CB, with the capacity to alter the autonomic control of the heart and vascular function and structure in CIH.

Management of Pulmonary Hypertension in the Context of Heart Failure with Preserved Ejection Fraction

PURPOSE OF REVIEW

To review the current evidence and modalities for treating pulmonary hypertension (PH) in heart failure with preserved ejection fraction (HFpEF).

RECENT FINDINGS

In recent years, several therapies have been developed that improve morbidity in HFpEF, though these studies have not specifically studied patients with PF-HFpEF. Multiple trials of therapies specifically targeting the pulmonary vasculature such as phosphodiesterase (PDE) inhibitors, prostacyclin analogs, endothelin receptor antagonists (ERA), and soluble guanylate cyclase stimulators have also been conducted. However, these therapies demonstrated lack of consistency in improving hemodynamics or functional outcomes in PH-HFpEF. There is limited evidence to support the use of pulmonary vasculature-targeting therapies in PH-HFpEF. The mainstay of therapy remains the treatment of the underlying HFpEF condition. There is emerging evidence that newer HF therapies such as sodium-glucose transporter 2 inhibitors and angiotensin-receptor-neprilysin inhibitors are associated with improved hemodynamics and quality of life of patients with PH-HFpEF. There is also a growing realization that more robust phenotyping PH and right ventricular (RV) function may hold promise for therapeutic strategies for patients with PH-HFpEF.

Sacubitril/valsartan inhibits the proliferation of vascular smooth muscle cells through notch signaling and ERK1/2 pathway

AIMS

To explore the role and mechanism of Notch signaling and ERK1/2 pathway in the inhibitory effect of sacubitril/valsartan on the proliferation of vascular smooth muscle cells (VSMCs).

MAIN METHODS

Human aortic vascular smooth muscle cells (HA-VSMCs) were cultured in vitro. The proliferating VSMCs were divided into three groups as control group, Ang II group and Ang II + sacubitril/valsartan group. Cell proliferation and migration were detected by CCK8 and scratch test respectively. The mRNA and protein expression of PCNA, MMP-9, Notch1 and Jagged-1 were detected by qRT-PCR and Western blot respectively. The p-ERK1/2 expression was detected by Western blot.

KEY FINDINGS

Compared with the control group, proliferation and migration of VSMCs and the expression of PCNA, MMP-9, Notch1, Jagged-1 and p-ERK1/2 was increased in Ang II group. Sacubitril/valsartan significantly reduced the proliferation and migration. Additionally, pretreatment with sacubitril/valsartan reduced the PCNA, MMP-9, Notch1, Jagged-1 and p-ERK1/2 expression.

Therapeutic Approaches in Pulmonary Arterial Hypertension with Beneficial Effects on Right Ventricular Function-Preclinical Studies

Pulmonary hypertension (PH) is a progressive condition that affects the pulmonary vessels, but its main prognostic factor is the right ventricle (RV) function. Many mice/rat models are used for research in PAH, but results fail to translate to clinical trials. This study reviews studies that test interventions on pulmonary artery banding (PAB), a model of isolated RV disfunction, and PH models. Multiple tested drugs both improved pulmonary vascular hemodynamics in PH models and improved RV structure and function in PAB animals. PH models and PAB animals frequently exhibited similar results (73.1% concordance). Macitentan, sildenafil, and tadalafil improved most tested pathophysiological parameters in PH models, but almost none in PAB animals. Results are frequently not consistent with other studies, possibly due to the methodology, which greatly varied. Some research groups start treating the animals immediately, and others wait up to 4 weeks from model induction. Treatment duration and choice of anaesthetic are other important differences. This review shows that many drugs currently under research for PAH have a cardioprotective effect on animals that may translate to humans. However, a uniformization of methods may increase comparability between studies and, thus, improve translation to clinical trials.

Sacubitril/valsartan mitigated intermittent hypoxia related intestinal microbiota alteration and aortic injury

OBJECTIVE

To investigate the influence of sacubitril valsartan sodium (SVS) on chronic intermittent hypoxia (IH) related gut microbiome composition alteration and aortic injury.

METHODS

Experiments were performed using SD rats, which were divided into three groups: control, IH, and SVS group. O2 concentration was decreased to 7-8% at nadir approximately every 3 min in IH group (8 h per day for 6 weeks) or was left unchanged in control group. Rats in SVS group were orally gavaged with SVS at the dosage of 30 mg/kg/day (2 weeks after chronic IH exposure). At week 6, fecal and aortic samples were harvested for 16 s rDNA analysis and histological analysis, respectively.

RESULTS

Principal coordinate analysis and non-metric multidimensional scaling analysis indicated that the bacterial community was altered by chronic IH exposure, while SVS treatment restored the intestinal microbial communities. Further analysis showed that IH decreased the relative abundance of Lactobacillus and Prevotella, while rats treated with SVS was enriched with Firmicutes, Bacilli, Prevotellaceae, and Lactobacillus, which was similar to control rats. Immunohistochemical staining showed that SVS prevented the upregulation of transforming growth factor-β1 and tumor necrosis factor-alpha in the aorta.

CONCLUSION

SVS prevented aortic adverse response to IH, possibly through modulating intestinal microbiota.

Preventive effect of LCZ696 on hypoxic pulmonary hypertension in rats via regulating the PI3K/AKT signaling pathway

Hypoxic pulmonary hypertension (HPH) is a devastating disease worldwide; however, effective therapeutic drugs are lacking. This study investigated the effects and underlying mechanisms of LCZ696 treatment on hypoxia-induced pulmonary hypertension. Male Sprague-Dawley (SD) rats were kept in a hypobaric chamber with an oxygen concentration of 5% for 4 weeks. Rats were treated with either LCZ696 (18 mg/kg, 36 mg/kg, and 72 mg/kg) or sildenafil. The mean pulmonary artery pressure (mPAP), right ventricle hypertrophy index (RVHI), and lung system index were measured. Hematoxylin-eosin (HE) staining, Masson staining, and immunofluorescence staining were used for histological analysis. Enzyme linked immunosorbent assay (ELISA) kits were used to determine the concentrations of inflammatory and hypoxia-related factors. Western blotting was used to examine the expression of apoptotic and PI3K/AKT signaling pathway proteins in rat lung tissue. Hypoxia increased mPAP, RVHI, and lung system index and induced pulmonary vascular remodeling, pulmonary arteriomyosis, and pulmonary artery fibrosis. LCZ696 treatment reduced the increase in mPAP, RVHI, and the lung system index and ameliorated the induced pathological changes. Hypoxia upregulated expression of NF-kB, TNF-α, IL-6, HIF-1α, and Vascular endothelial growth factor (VEGF), decreased the ratio of Bax/Bcl-2, and activated the PI3K/AKT signaling pathway in lung tissue, and these effects were partially reversed by treatment with LCZ696. These results demonstrated that LCZ696 can ameliorate hypoxia-induced HPH by suppressing apoptosis, inhibiting the inflammatory response, and inhibiting the PI3K/AKT signaling pathway. It provides a reference for clinical rational drug use and lays a foundation for the study of HPH therapeutic drugs.

Arsenic trioxide demonstrates efficacy in a mouse model of preclinical systemic sclerosis

BACKGROUND

Uncontrolled T-cell activation plays a key role in systemic sclerosis (SSc). Arsenic trioxide (ATO) has immunological effects and has demonstrated potential in preclinical SSc models. In this study, we assessed the efficacy of ATO in Fra2 transgenic (Fra2TG) mice, which develop severe vascular remodeling of pulmonary arterioles and nonspecific interstitial pneumonia-like lung disease, closely resembling human SSc-associated pulmonary hypertension, therefore partially resembling to the SSc human disease.

METHODS

The efficacy of ATO in Fra2TG mice was evaluated through histological scoring and determination of cell infiltration. Fibrotic changes in the lungs were assessed by measuring collagen content biochemically, using second harmonic generation to measure fibrillar collagen, and imaging via computed tomography. Cardiovascular effects were determined by measuring right ventricular systolic pressure and vessel remodeling. The mechanism of action of ATO was then investigated by analyzing lung cell infiltrates using flow cytometry and bulk RNA with sequencing techniques.

RESULTS

After ATO treatment, the Ashcroft histological score was substantially decreased by 33% in ATO-treated mice compared to control mice. Other investigations of fibrotic markers showed a trend of reduction in various measurements of fibrosis, but the differences did not reach significance. Further cardiovascular investigations revealed convergent findings supporting a beneficial effect of ATO, with reduced right ventricular systolic pressure and medial wall thickness, and a significant decrease in the number of muscularized distal pulmonary arteries in ATO-treated Fra2TG mice compared to untreated Fra2TG mice. Additionally, inflammatory cell infiltration was also markedly reduced in lesioned lungs. A reduction in the frequency of CD4 + and T effector memory cells, and an increase in the percentage of CD4 + T naive cells in the lungs of ATO-treated Fra-2TG mice, was observed when compared to PBS group Fra-2Tg mice. RNA-seq analysis of ATO-treated mouse lungs revealed a downregulation of biological pathways associated with immune activity and inflammation, such as T-cell activation, regulation of leucocyte activation, leucocyte cell-cell adhesion, and regulation of lymphocyte activation.

CONCLUSIONS

Our results suggest the clinical relevance of ATO treatment in SSc. Using the Fra2TG mouse model, we observed significant lung histological changes, a trend towards a decrease in various fibrotic makers, and a strong reduction in vascular remodeling. The mechanism of action of ATO appears to involve a marked counteraction of the immune activation characteristic of SSc, particularly T-cell involvement. These findings pave the way for further studies in SSc.

Natural Targeting Potent ROS-Eliminating Tungsten-Based Polyoxometalate Nanodots for Efficient Treatment of Pulmonary Hypertension

Pulmonary hypertension (PH) is a disease of pulmonary artery stenosis and blockage caused by abnormal pulmonary artery smooth muscle cells (PASMCs), with high morbidity and mortality. High levels of reactive oxygen species (ROS) in pulmonary arteries play a crucial role in inducing phenotypic switch and abnormal proliferation of PASMCs. However, antioxidants are rarely approved for the treatment of PH because of a lack of targeting and low bioavailability. In this study, the presence of an enhanced permeability and retention effect (EPR)-like effect in the pulmonary arteries of PH is revealed by tissue transmission electron microscopy (TEM). Subsequently, for the first time, tungsten-based polyoxometalate nanodots (WNDs) are developed with potent elimination of multiple ROS for efficient treatment of PH thanks to the high proportion of reduced W5+ . WNDs are effectively enriched in the pulmonary artery by intravenous injection because of the EPR-like effect of PH, and significantly prevent the abnormal proliferation of PASMCs, greatly improve the remodeling of pulmonary arteries, and ultimately improve right heart function. In conclusion, this work provides a novel and effective solution to the dilemma of targeting ROS for the treatment of PH.

Recent Advances and Future Prospects of Treatment of Pulmonary Hypertension

Pulmonary hypertension is one of the difficult situations to treat. Complex pathophysiology, association of the multiple comorbidities make clinical scenario challenging. Recently it is being shown that patients who had recovered from coronavirus disease infection, are at risk of developing pulmonary hypertension. Studies on animals have been going on to find out newer treatment options. There are recent advancements in the treatment of pulmonary hypertension. Role of anticoagulation, recombinant fusion proteins, stem cell therapy are emerging as therapeutic options for affected patients. SGLT2 inhibitors have potential to have beneficial effects on pulmonary hypertension. Apart from the medical managements, advanced interventions are also getting popular. In this review article, the authors have discussed pathophysiology, recent advancement of treatments including coronavirus disease patients, and future aspect of managing pulmonary hypertension. We have highlighted treatment options for patients with sleep apnea, interstitial lung disease to discuss the challenges and possible options to manage those patients.

LCZ696 (sacubitril/valsartan) inhibits pulmonary hypertension induced right ventricular remodeling by targeting pyruvate dehydrogenase kinase 4

BACKGROUND

Right ventricular (RV) function is a major prognostic factor in patients with cardiopulmonary disease. Effective medical therapies are available for left heart failure, but they are usually less effective or even ineffective in right heart failure. Here, we tested the hypothesis that LCZ696 (sacubitril/valsartan) can attenuate pressure overload-induced RV remodeling by inhibiting pyruvate dehydrogenase kinase 4 (PDK4).

METHODS

Adult male C57 mice were subjected to transverse aortic constriction (TAC), pulmonary artery constriction (PAC), or sham surgery. Bioinformatics analysis was used to screen for common differentially expressed genes (DEGs) between TAC and PAC. Chemical compounds targeting DEGs were predicted by molecular docking analysis. Effects of LCZ696 on PAC-induced RV remodeling and the associated PDK4-related mechanisms were investigated.

RESULTS

We found 60 common DEGs between PAC and TAC, and Pdk4 was one of the downregulated DEGs. From 47 chemical compounds with potential cardiovascular activity and PDK4 protein binding ability, we selected LCZ696 to treat PAC-induced RV remodeling because of its high docking score for binding PDK4. Compared with vehicle-treated PAC mice, LCZ696-treated mice had significantly smaller RV wall thickness and RV diameters, less myocardial fibrosis, lower expression of PDK4 protein, and less phosphorylation of glycogen synthase kinase-3β (p-GSK3β). In PAC mice, overexpression of Pdk4 blocked the inhibitory effect of LCZ696 on RV remodeling, whereas conditional knockout of Pdk4 attenuated PAC-induced RV remodeling.

CONCLUSIONS

Pdk4 is a common therapeutic target for pressure overload-induced left ventricular and RV remodeling, and LCZ696 attenuates RV remodeling by downregulating Pdk4 and inhibiting PDK4/p-GSK3β signal.

Bioinformatics exploration of potential common therapeutic targets for systemic and pulmonary arterial hypertension-induced myocardial hypertrophy

Systemic and pulmonary arterial hypertension (PAH) can induce left and right ventricular hypertrophy, respectively, but common therapeutic targets for both left and right hypertrophy are limited. In this study, we attempt to explore potential common therapeutic targets and screen out potential target drugs for further study. Cardiac mRNA expression profiles in mice with transverse aortic constriction (TAC) and pulmonary arterial constriction (PAC) are obtained from online databases. After bioinformatics analyses, we generate TAC and PAC mouse models to validate the phenotypes of cardiac remodelling as well as the identified hub genes. Bioinformatics analyses show that there are 214 independent differentially expressed genes (DEGs) in GSE136308 (TAC related) and 2607 independent DEGs in GSE30922 (PAC related), while 547 shared DEGs are associated with the function of the extracellular matrix (ECM) or involved in the PI3K-Akt signaling pathway, cytokine-cytokine receptor interactions, and ECM-receptor interactions. We identifyd Fn1, Il6, Col1a1, Igf1, Col1a2, Timp1, Col3a1, Cd44, Ctgf and Postn as hub genes of the shared DEGs, and most of them are associated with myocardial fibrosis. Those hub genes and phenotypes of cardiac remodelling are validated in our TAC and PAC mouse models. Furthermore, we identify dehydroisoandrosterone (DHEA), iloprost and 4,5-dianilinophthalimide (DAPH) as potential therapeutic drugs targeting both left and right ventricular hypertrophy and validate the effect of DHEA. These findings suggest that DHEA could be an effective drug for pressure overload-induced left or right ventricular hypertrophy by regulating the shared hub differentially expressed genes associated with fibrosis.

The emerging role of sacubitril/valsartan in pulmonary hypertension with heart failure

Pulmonary hypertension due to left heart disease (PH-LHD) represents approximately 65%-80% of all patients with PH. The progression, prognosis, and mortality of individuals with left heart failure (LHF) are significantly influenced by PH and right ventricular (RV) dysfunction. Consequently, cardiologists should devote ample attention to the interplay between HF and PH. Patients with PH and HF may not receive optimal benefits from the therapeutic effects of prostaglandins, endothelin receptor antagonists, or phosphodiesterase inhibitors, which are specific drugs for pulmonary arterial hypertension (PAH). Sacubitril/valsartan, the angiotensin receptor II blocker-neprilysin inhibitor (ARNI), was recommended as the first-line therapy for patients with heart failure with reduced ejection fraction (HFrEF) by the 2021 European Society of Cardiology Guidelines. Although ARNI is effective in treating left ventricular (LV) enlargement and lower ejection fraction, its efficacy in treating individuals with PH and HF remains underexplored. Considering its vasodilatory effect at the pre-capillary level and a natriuretic drainage role at the post-capillary level, ARNI is believed to have a broad range of potential applications in treating PH-LHD. This review discusses the fundamental pathophysiological connections between PH and HF, emphasizing the latest research and potential benefits of ARNI in PH with various types of LHF and RV dysfunction.

The history and mystery of sacubitril/valsartan: From clinical trial to the real world

Heart failure is a serious threat to human health, with morbidity and mortality rates increasing despite the existence of multiple treatment options. Therefore, it is necessary to identify new therapeutic targets for this disease. Sacubitril/valsartan is a supramolecular sodium salt complex of the enkephalinase inhibitor prodrug sacubitril and the angiotensin receptor blocker valsartan. Its combined action increases endogenous natriuretic peptides while inhibiting the renin-angiotensin-aldosterone system and exerting cardioprotective effects. Clinical evidence suggests that sacubitril/valsartan is superior to conventional renin-angiotensin-aldosterone inhibitor therapy for patients with reduced ejection fraction heart failure who can tolerate angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers. The therapy reduces the risk of heart failure hospitalization, cardiovascular mortality, and all-cause mortality and has a better safety and tolerability record. This review describes the potential pathophysiological mechanisms of cardiomyocyte injury amelioration by sacubitril/valsartan. We explore the protective effects of sacubitril/valsartan and outline the therapeutic value in patients with heart failure by summarizing the results of recent large clinical trials. Furthermore, a preliminary outlook shows that sacubitril/valsartan may be effective at treating other diseases, and provides some exploratory observations that lay the foundation for future studies on this drug.

AMPK activation by metformin protects against pulmonary hypertension in rats and relaxes isolated human pulmonary artery

Pulmonary hypertension (PH) is associated with pulmonary vasoconstriction and endothelial dysfunction leading to impaired nitric oxide (NO) and prostacyclin (PGI₂) pathways. Metformin, the first line treatment for type 2 diabetes and AMP-activated protein kinase (AMPK) activator, has been recently highlighted as a potential PH treatment. AMPK activation has been reported to improve endothelial function by enhancing endothelial NO synthase (eNOS) activity and to have relaxant effects in blood vessels. In this study, we examined the effect of metformin treatment on PH as well as on NO and PGI₂ pathways in monocrotaline (MCT)-injected rats with established PH. Moreover, we investigated the anti-contractile effects of AMPK activators on endothelium-denuded human pulmonary arteries (HPA) from Non-PH and Group 3 PH patients (due to lung diseases and/or hypoxia). Furthermore, we explored the interaction between treprostinil and the AMPK/eNOS pathway. Our results showed that metformin protected against PH progression in MCT rats where it reduced the mean pulmonary artery pressure, pulmonary vascular remodeling and right ventricular hypertrophy and fibrosis compared to vehicle-treated MCT rats. The protective effects on rat lungs were mediated in part by increasing eNOS activity and protein kinase G-1 expression but not through the PGI₂ pathway. In addition, incubation with AMPK activators reduced the phenylephrine-induced contraction of endothelium-denuded HPA from Non-PH and PH patients. Finally, treprostinil also augmented eNOS activity in HPA smooth muscle cells. In conclusion, we found that AMPK activation can enhance the NO pathway, attenuate vasoconstriction by direct effects on smooth muscles, and reverse established MCT-induced PH in rats.

The efficacy and safety of Sacubitril/Valsartan on pulmonary hypertension in hemodialysis patients

BACKGROUND

Pulmonary hypertension (PH) is a common complication of end-stage renal disease which is associated with adverse outcomes including all-cause mortality and cardiovascular events. Recent studies have demonstrated that Sacubitril/Valsartan (Sac/Val) as an enkephalinase inhibitor and angiotensin II receptor blocker could reduce pulmonary artery systolic pressure (PASP) and improve the prognosis of patients with heart failure. However, whether Sac/Val is effective in hemodialysis (HD) patients with PH is essentially unknown. In this retrospective study, we aimed to evaluate the efficacy and safety of Sac/Val in the treatment of PH in HD patients.

METHODS

A total of 122 HD patients with PH were divided into Sac/Val group (n = 71) and ARBs group (n = 51) based on the treatment regimen. The PASP, other cardiac parameters measured by echocardiography, and cardiac biomarkers including N-terminal fragment of BNP (NT-proBNP) and cardiac troponin I (cTnI) were observed at baseline and 3 months after treatment.

RESULTS

There were no significant differences in the baseline characteristics between the two groups. PASP decreased significantly from 45(38, 54) to 28(21, 40) mmHg in Sac/Val group (p < 0.001). PASP reduced from 41(37, 51) to 34(27, 44) mmHg in ARBs group (p < 0.001), and the decrease was more pronounced in the Sac/Val group (p < 0.001). In addition, improvements in the right atrial diameter (RAD), left ventricular diameter (LVD), left ventricular posterior wall thickness (LVPWT), left atrial diameter (LAD), pulmonary artery diameter (PAD), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), and fractional shortening (FS) were found in Sac/Val group (ps < 0.05). After 3 months, LVD, LAD, LVEDV, LVESV, LVEF, SV, and PASP were significantly improved in Sac/Val group compared with ARBs group (ps <0.05). Significant reduction in NT-proBNP [35,000 (15,000, 70,000) pg/ml vs. 7,042 (3,126, 29,060) pg/ml, p < 0.001] and cTnI [0.056(0.031, 0.085) ng/ml vs. 0.036 (0.012, 0.056) ng/ml, p < 0.001) were observed in Sac/Val group. No significant differences were observed in adverse events between the two groups (ps > 0.05).

CONCLUSION

Sac/Val seems to be an efficacious regimen in PH with favorable safety and has huge prospects for treating PH in HD patients.

The comparative effects of sacubitril/valsartan versus enalapril on pulmonary hypertension due to heart failure with a reduced ejection fraction

The purpose of this study was to investigate the effects of sacubitril/valsartan on right ventricular (RV) function in patients with pulmonary hypertension (PH) due to heart failure with reduced ejection fraction (HFrEF). We prospectively enrolled patients with HFrEF-induced PH admitted to the Department of Cardiology between August 2018 and December 2019. Patients were randomized to receive oral treatment with sacubitril/valsartan or enalapril. Epidemiological data were recorded before treatment. Echocardiography was performed at admission and 6 months of follow-up, and all parameters were compared. Major adverse cardiac events (MACEs) were compared between baseline and 6 months follow-up. There were no significant differences in the baseline characteristics between the two groups. After 6 months of treatment, both treatment groups improved the following parameters from baseline (mean ± SD): left atrium, left ventricle, the left ventricular ejection function (LVEF), RV systolic function (the tricuspid annular plane systolic excursion [TAPSE], the systolic pulmonary artery pressure [sPAP], and TAPSE/sPAP). After 6 months, sacubitril/valsartan improved significantly the following parameters compared with enalapril (all p < 0.05): LVEF (47.07 ± 6.93% vs. 43.47 ± 7.95%); TAPSE (15.33 ± 1.31 vs. 14.78 ± 1.36 mm); sPAP (36.76 ± 14.32 vs. 42.26 ± 12.07 mmHg); and TAPSE/sPAP ratio (0.50 ± 0.23 vs. 0.39 ± 0.14), respectively. There was no difference in readmissions due to recurrent heart failure. Sacubitril/valsartan seems to provide more beneficial effects among patients with HFrEF-induced PH to improve RV function, along with a decrease in pulmonary pressure.

Hotspots and frontiers in pulmonary arterial hypertension research: a bibliometric and visualization analysis from 2011 to 2020

Pulmonary arterial hypertension (PAH) is a group of devastating and progressive disorders, resulting in relentless increases in pulmonary vascular resistance. The number of studies related to PAH has been increasing in recent years. Our study aims to illustrate trends in PAH research over the past decade using bibliometric analysis. Science Citation Index-Expanded was adopted to search studies concerning PAH between 2011 and 2020. The bibliographic information was converted and analyzed automatically using a bibliometric package in R software and citespace. The annual quantity of publications on PAH showed an overall increase last decade. The United States was the most prolific country with 2,479 publications, and it was also the country that cooperated most with other countries. Hôpital Bicêtre made important research achievements on PAH and was a leader in study cooperation. Marc Humbert led the PAH field by publishing 150 articles in the past decade. During the past decade, there was a close transnational relation among countries or regions, institutions and authors. Further, Circulation was the most cited journal, followed by the Journal of the American College of Cardiology and the American Journal of Respiratory and Critical Care Medicine, with 3,895, 3,406, and 3,170 citations, respectively. The global research status and trend of PAH are deeply understood for the first time using bibliometric and visual methods, and the results of our study bring us a valuable reference for clinical researchers.

This is the first study to illustrate trends in pulmonary arterial hypertension research using bibliometric analysis.

Our study provides extensive and in-depth directions for researchers.

Our study may benefit further researches on the etiology, diagnosis, and treatment of pulmonary arterial hypertension.

Loss of cAbl Tyrosine Kinase in Pulmonary Arterial Hypertension Causes Dysfunction of Vascular Endothelial Cells

Pulmonary arterial hypertension (PAH) is a progressive and fatal disease characterized by the dysfunction of pulmonary endothelial cells (ECs) and obstructive vascular remodeling. The non-receptor tyrosine kinase c-Abelson (cAbl) plays central roles in regulating cell-cycle arrest, apoptosis, and senescence after cellular stress. We hypothesized that cAbl is down-activated in experimental and human PAH, thus leading to reduced DNA integrity and angiogenic capacity of pulmonary ECs from PAH patients (PAH-ECs). We found cAbl and phosphorylated cAbl levels to be lower in the endothelium of remodeled pulmonary vessels in the lungs of PAH patients than controls. Similar observations were obtained for the lungs of sugen+hypoxia (SuHx) and monocrotaline (MCT) rats with established pulmonary hypertension. These in situ abnormalities were also replicated in vitro, with cultured PAH-ECs displaying lower cAbl expression and activity and an altered DNA damage response and capacity of tube formation. Downregulation of cAbl by RNA-interference in Control-ECs or its inhibition with dasatinib resulted in genomic instability and the failure to form tubes, whereas upregulation of cAbl with DPH reduced DNA damage and apoptosis in PAH-ECs. Finally, we establish the existence of crosstalk between cAbl and bone morphogenetic protein receptor type II (BMPRII). This work identifies the loss of cAbl signaling as a novel contributor to pulmonary EC dysfunction associated with PAH.

Predictors of right ventricular function improvement with sacubitril/valsartan in a real-life population of patients with chronic heart failure

Background

Observational studies have demonstrated that treatment with sacubitril/valsartan may improve left ventricular (LV) systolic and diastolic function in subjects with reduced LV ejection fraction (LVEF) in real‐world studies. Subjects with heart failure and reduced EF (HFrEF), however, are also characterized by an impaired right ventricular (RV) function. We therefore aimed to evaluate whether also RV function may improve after S/V therapy and possible predictors of RV improvement could be identified at echocardiography and tissue Doppler imaging.

Methods

Fifty consecutive patients (67 ± 8 years, LVEF 28 ± 6%, male 86%) with chronic HFrEF and NYHA class II‐III were followed up for 6 months after therapy with S/V. LV&RV function was assessed at baseline and after 6 months of therapy.

Results

After 6‐month therapy with S/V a significant improvement was shown in the following echocardiography parameters assessing RV function: PAsP (31 ± 11 vs. 35 ± 10 mmHg, p < 0.001), TAPSE (19 ± 3 vs. 18 ± 3 mm, p < 0.001), RV FAC (38 ± 7 vs. 34 ± 6 mm, p < 0.001), RV S’ (12 ± 2 vs. 10 ± 2 cm/s, p < 0.001), RV‐FW‐LS (−20 ± 5 vs. −18 ± 5%, p < 0.001), RV‐4Ch‐LS (−16 ± 5 vs. −14 ± 5%, p < 0.001). At multivariable analysis improvement in RV‐FW‐LS was associated to baseline levels of RV S’ (r 0.75, p < 0.01) and RAV (r –0.32, p < 0.05).

Conclusions

In a real‐world scenario, 6‐month therapy with S/V was associated with an improved RV function in HFrEF. RV function improvement may be predicted by assessing baseline RV S’ and right atrial volume values.

Carbonic anhydrase inhibition improves pulmonary artery reactivity and nitric oxide-mediated relaxation in sugen-hypoxia model of pulmonary hypertension

Pulmonary hypertension (PH) is a serious disease with pulmonary arterial fibrotic remodeling and limited responsiveness to vasodilators. Our data suggest that mild acidosis induced by carbonic anhydrase inhibition could ameliorate PH, but the vascular mechanisms are unclear. We tested the hypothesis that carbonic anhydrase inhibition ameliorates PH by improving pulmonary vascular reactivity and relaxation mechanisms. Male Sprague-Dawley rats were either control normoxic (Nx), or injected with Sugen 5416 (20 mg/kg, sc) and subjected to hypoxia (9% O2) (Su + Hx), or Su + Hx treated with acetazolamide (ACTZ, 100 mg/kg/day, in drinking water). After measuring the hemodynamics, right ventricular hypertrophy was assessed by Fulton's Index; vascular function was measured in pulmonary artery, aorta, and mesenteric arteries; and pulmonary arteriolar remodeling was assessed in lung sections. Right ventricular systolic pressure and Fulton's Index were increased in Su + Hx and reduced in Su + Hx + ACTZ rats. Pulmonary artery contraction to KCl and phenylephrine were reduced in Su + Hx and improved in Su + Hx + ACTZ. Acetylcholine (ACh)-induced relaxation and nitrate/nitrite production were reduced in pulmonary artery of Su + Hx and improved in Su + Hx + ACTZ. ACh relaxation was blocked by nitric oxide (NO) synthase and guanylate cyclase inhibitors, supporting a role of NO-cGMP. Sodium nitroprusside (SNP)-induced relaxation was reduced in pulmonary artery of Su + Hx, and ACTZ enhanced relaxation to SNP. Contraction/relaxation were not different in aorta or mesenteric arteries of all groups. Pulmonary arterioles showed wall thickening in Su + Hx that was ameliorated in Su + Hx + ACTZ. Thus, amelioration of pulmonary hemodynamics during carbonic anhydrase inhibition involves improved pulmonary artery reactivity and NO-mediated relaxation and may enhance responsiveness to vasodilator therapies in PH.

Fasudil Dichloroacetate Alleviates SU5416/Hypoxia-Induced Pulmonary Arterial Hypertension by Ameliorating Dysfunction of Pulmonary Arterial Smooth Muscle Cells

Background

Pulmonary arterial hypertension (PAH) is an incurable disease that urgently needs therapeutic approaches. Based on the therapeutic effects of fasudil and dichloroacetate (DCA) on PAH, we aimed to explore the effects and potential mechanism of a new salt, fasudil dichloroacetate (FDCA), in a SU5416 plus hypoxia (SuHx)-induced rat model of PAH.

Methods

The rat model of PAH was established by a single subcutaneous injection of SU5416 (20 mg/kg) followed by hypoxia (10% O₂) exposure for 3 weeks. FDCA (15, 45, or 135 mg/kg i.g. daily) or the positive control, bosentan (100 mg/kg i.g. daily), were administered from the first day after SU5416 injection. After 3-week hypoxia, hemodynamic parameters, and histological changes of the pulmonary arterial vessels and right ventricle (RV) were assessed. Additionally, in vitro, the effects of FDCA (50 μM), compared with equimolar doses of fasudil, DCA, or fasudil+DCA, on the proliferation, migration, and contraction of human pulmonary arterial smooth muscle cell (PASMC) under hypoxia (1% O₂) were evaluated.

Results

FDCA dose-dependently attenuated SuHx-induced PAH, with significant reductions in RV systolic pressure, pulmonary artery wall thickness, pulmonary vessel muscularization, perivascular fibrosis, as well as RV hypertrophy and fibrosis. In vitro, FDCA inhibited hypoxia-induced PASMC proliferation, migration, and contraction to a greater degree than fasudil or DCA alone by restoring mitochondrial function, reducing intracellular Ca²⁺, and inhibiting calcium/calmodulin-dependent kinase (Ca²⁺/CaMK) activity as well as Rho-kinase activity.

Conclusion

FDCA ameliorates hypoxia-induced PASMC dysfunction by inhibiting both Ca²⁺/CaMK and Rho-kinase signaling pathways, as well as maintaining mitochondrial homeostasis, thus alleviating SuHx-induced PAH.